11.1.2. THE BASE-BAND INTEGRATED CIRCUIT (BBIC)
The National SC14405 BBIC (IC1) is a CMOS device designed to handle all the audio, signal and
data processing needed in a DECT handset. It contains two microprocessors - one general
purpose - while the other
ì
burst mode controllerî takes care of DECT specific physical layer and
radio section control.The BBIC also contains the ADPCM transcoders, a low power 14 bit codec
(ADC/DAC), various other ADCís, DACís and timers, a UART for data communication with RF
unit, a gaussian filter for the DECT GFSK modulation method, clock and data recovery circuits,
a clock oscillator circuit, a battery management circuit, and a pair of gaincontrollable amplifiers
for the microphone and earpiece.
11.1.3. LCD DISPLAY, AND DISPLAY DRIVER (SEE Fig. 26)
The LCD display also receives data via a serial interface. Serial data is sent to LCD display on
pin 3 (TP70). The RS signal (pin 1, TP67) is used by the BBIC to send either commands or data.
Circuit Diagram
11.1.4. AUDIO PATH - TX AUDIO (SEE Fig. 27)
Balanced audio from the microphone (TP40 and TP41) enters the BBIC at pins 61 and 63. A
balanced bias voltage for the (“electret” type) microphone is supplied by the BBIC from pins 60
and 64 via R31 and R32. This supply is de-coupled by R22, R27, C21, C28, and C22. RF de-
coupling of the microphone signal is provided by R27, C25, R28, C26, R24, R25, and C20. The
microphone audio signals are coupled to the BBIC via C22 and C23, which provide some high
pass filtering. / In the BBIC audio passes through the gain-controlled microphone amplifier, into
the ADC part of the codec, where it is sampled and turned into digital data. The burst mode
controller then processes this raw data (called the B-field) performing encryption and
scrambling, adding the various other fields that go together to produce the GAP standard DECT
frame, assigning to a time slot and channel etc. The data then passes through the gaussian filter
to emerge on pin 20 as TRADAT.
11.1.5. AUDIO PATH - RX AUDIO (SEE Fig. 27)
23
Содержание KX-TCD952NLB
Страница 2: ...1 LOCATION OF CONTROLS 2...
Страница 3: ...2 DISASSEMBLY INSTRUCUTIONS 3...
Страница 9: ...4 4 SELECTING THE HANDSET RINGER VOLUME 4 5 SELECTING THE BASE UNIT RINGER VOLUME 9...
Страница 11: ...6 BLOCK DIAGRAM RF UNIT BASE UNIT 11...
Страница 12: ...7 BLOCK DIAGRAM BASEBAND SECTION AND LINE INTERFACE BASE UNIT 12...
Страница 20: ...9 BLOCK DIAGRAM RF UNIT HANDSET 20...
Страница 21: ...10 BLOCK DIAGRAM BASE BAND SECTION HANDSET 21...
Страница 36: ...36...
Страница 37: ...16 2 HANDSET LINK 37...
Страница 38: ...38...
Страница 39: ...39...
Страница 40: ...16 3 HANDSET DOES NOT LINK 16 4 BASE UNIT DOES NOT CHARGE 40...
Страница 41: ...16 5 HANDSET DOES NOT CHARGE 41...
Страница 42: ...16 6 NO VOICE RECEPTION 42...
Страница 43: ...16 7 NO VOICE TRANSMISSION 16 8 BASE UNIT DOES NOT LINK 43...
Страница 44: ...17 CABINET AND ELECTRICAL PARTS LOCATION BASE UNIT 44...
Страница 45: ...18 CABINET AND ELECTRICAL PARTS LOCATION HANDSET 45...
Страница 46: ...19 ACCESSORIES AND PACKING MATERIALS 46...
Страница 58: ...22 1 SCHEMATIC DIAGRAM HANDSET U Q KXTCD952NLB UK Printed in Japan 58...